Various forms of attaching structures or connecting members have been heretofore provided for securing adjacent frame members in adjusted positions relative to each other. However, most of these attaching structures or connecting members are constructed in a manner whereby they are readily viewable from the front faces of the associated frames. Further, these attaching structures or connecting members which have been previously known have not been constructed so as to enable various adjustments of adjacent frames relative to each other.
Examples of previously known attaching structures or connecting members including some of the operational characteristics of the instant invention are disclosed in U.S. Pat. Nos. 923,394, 2,317,708, 2,616,197, 3,722,122 and 3,783,543.